Train operating system



Filed July 13, 1929 5 Sheets-Sheet l INVENTO/T aldzhhanrm/ by g l- A cry July 19, 1938. A. G. SHAVER TRAIN OPERATING SYSTEM Filed July 13, 1929 3 Sheets-Sheet 2 ONN INVENTOR m tt a A. G. SHAVER TRAIN orsmvrme SYSTEM Filed July 13, 1929 3 Sheets-Sheet 3 lNI/ENTOR I I Wot/1.

Jul 19, 1938.

Patented July 19, 1938 UNITED .STATES PATENT OFFICE TRAIN OPERATING SYSTEM 39 Claims.

This invention relates to train operating systems and more particularly to a system in which there may be communication direct between the dispatchers and trains and between the con ductors and enginemen of trains, for the transmission of orders and information; the dispatchers may operate signals at selected points, as at passing tracks, for the control of train movements; and switches may be operated to divert trains from main lines to passing tracks and return automatically to normal position, etc.

It is now the practice of railway train dispatchers to transmit orders for a train to an operator out along the railroad at a point in advance of the train. The-operator stops the train, or causes it to slow down, that it may be given the orders which he has for it. Such orders often pertain to a train diverting to a passing track to let another train pass. When the train reaches the passing track which it is to enter, it stops while an employee operates the track switch leading to the siding; the train enters the siding and, on clearing the main track, again stops while an employee returns the track switch to its normal or main track position.

The object of this invention is to provide a train operating system such that the dispatcher may give orders direct to the crew of the train, whether the train be moving or standing still, thus making wayside operators unnecessary for transmitting orders and eliminating stops and slow-downs of the train to pick up orders. Also, as a check against the misunderstanding and non-fulfillment oi the orders on the part of the crew of the train, the dispatcher may control the signals at passing tracks to insure stopping of trains in case the orders are misunderstood or overlooked. After receiving the orders from the dispatcher, the conductor and engincman may 40 communicate with each other in regard to carrying out the said orders. Further, means are provided such that when the train approaches a passing siding, the track switch may be operated for the train to enter the siding without the train having'to stop for that purpose; and when the train has cleared the fouling point of the siding with the main line the track switch will automatically return to the normal position. Therefore, with the switch reversing as the train approaches it and returning to normal after the train has passed over it, stops of the train, such as now must be made under present practices, are avoided.

Additional objects are To provide a novel signaling means for calling attendants to receive a communication.

, To provide amplification at the transmitter of the signals used in communication;

To provide an intermediate circuit for communication wherein certain transpositions of conductors are made to minimize inductive noise disturbances;

To provide means admitting of communication between the train and the dispatcher continuously as the train proceeds from the main line onto the siding, and while on the siding;

To provide a track switch connecting and operating means which permits of trains operating through the switch trailing without being damaged or damaging the points of the switch;

To provide a switch locking means which locks the track switch for trains passing thereover in. the facing direction, but which does not lock the track switch for trains passing thereover in the trailing direction.

To provide an intermediate circuit for communication which includes both the main line and the siding;

To provide a switch operating means including a combination of power mechanism and switch stand control, the operation of either one of which is optional.

To provide power operated switch control means including a device which will lock the switch automatically in either the normal or reverse position through the force of a spring, but which requires power to be unlocked;

To provide a power operated track switch which may be controlled from either the roadside or from the train;

Other objects and advantages will appear as the description progresses.

In describing one embodiment of the invention in detail, reference will be made to the accompanying drawings in which:-

Fig. 1 illustrates diagrammatically a stretch of main track (part of an equipped railroad) with a siding leading therefrom. and means for carrying on communication between a train and a roadside station and between the head end and the rear end of a train.

Fig. 2 is a diagram oi the transmitting and receiving equipment on the train.

Fig, 3 illustrates diagrammatically a portion of the same stretch of railway track as Fig. l. but upon which are indicated the circuits and equipment concerned in the operation of the track switch.

Fig. 4 is a diagrammatic plan view of the mechanical features for operating and protecting the switch.

Fig. 5 is a section and diagrammatic partial elevation of the directional locking arrangement, on line KK of Fig. 4.

Fig. 6 is a cross section of part of the power mechanism for the switch.

Fig. 7 is a cross section of the locking device for the switch.

Fig. 8 is a diagrammatic view showing a part of a control rod for locking the switch.

Fig. 9 is a graphical view of the operation of the contacts in the circuit controller.

Fig. 10 is a diagrammatic view of the normal circuits, signaling means, communication transmitting means and communication receiving means with one stage of amplification for the transmitter, and two stages of amplification for the receiver, for the train communication station.

Fig. 11 is a diagrammatic view of the normal circuits, signaling means, communication transmitting means and communication receiving means, with one stage of amplification for the transmitter and two stages of amplification for the receiver, for the roadside communicating station.

Fig. 12 is a diagrammatic illustration of a slightly different arrangement of communicating circuits at a passing siding from that shown in Fig. l.

Communicating system.Thls is of the same general character and represents further developments and improvements over the systems illustrated and described in my pending applications Serial #227,932, filed October 22nd, 1927, Serial No. 304,483, filed September 7th, 1928, and Serial No. 306,905, filed September 19th, 1928. As is the case in the applications referred to, this invention provides for carrying on communication between the front end and the rear end of a train, and between either or both of the train stations and a wayside station. Normally the apparatus is set up to function to permit communication between the head and the rear end of the train to be carlied on at any time or at all times. Generally the wayside station is not in communicative relationship with the train unless certain connecting ap-' paratus is operated, including a transformer, as will be specifically described later; however, means are provided by which the train may automatically connect itself with a wayside station; further, apermanent connection may be made from the wayside station with an intermediate circuit for a train station in a prescribed territory. The several principal features comprised in this train communication system are: transmitting and receiving communicating sets on the train (usually in case of short trains only one set will be required on the train); an intermediate circuit which is in communicative relationship with the train carried sets and adapted to be placed in communicative relationship with the wayside station; a wayside station and circuit including a transmitting and receiving communicating set; and remote control or selective apparatus which makes it possible for the dispatcher or an attendant in the wayside station to connect the wayside circuit with the intermediate circuit and thus with the train in said intermediate circuit. This system of communication will be more particularly described in its use for operating railway trains, whereby the conductor and engineman of the train may communicate with each other, and the dispatcher in charge of the district may communicate with either or both of them.

In Fig. 1, SW is a track switch which connects the siding with the main line. A, B, C, D, E, I", G, H, 1, etc., are sections or track in said stretch. B, D, F, G and H are track section circuits with a relay therein in each case normally energized, as indicated by relays TB, TD. TF, TG and TH respectively. S2 and S3 are signals Governing train movements over the track switch SW along the main line. Si and B4 are signals governing train movements over the switch between the main line and the siding. YB, YD, YF, I1 and II are selector relays controlled by the dispatcher in his selective system through the conductors DI and D2 from the dispatchers station. WB, WD, WF and WG are transformers provided for connecting the intermediate circuit with the dispatchers wayside circuit, the first three being controlled respectively by the selector relays YB, YD and YF; and WG being controlled by track relay TH. The selector relays I1 and 18 are for the control of signals as will be more iully explained later in Fig. 3. T and RS and SOS are the transmitting and receiving communicating set and the selective operating set respectively in the dispatchers ofllce or wayside station. SM is a power mechanism for operating the track switch SW; SL is a power mechanism for operating lock plunger LP for locking and unlocking the track switch. I48 is a switch stand for also operating the switch SW by manual means. FPL is a facing point lock for locking the points of the switch, as the train approaches same in a direction facing the switch, shown in detail in Figs. 4, 5 and 8. SB is a spring buffer means in the control rod connecting the switch SW with the mechanism SM, and may be any one of several well known makes, as the mechanical switchman manufactured by Pettibone-Mulliken Co. Ill indicates a train in the intermediate section C. Conductors I00, 003. I05, I01, I09, Ill and H6 are located on the trackway, usually on the ties in the center of the track between the two track rails X and Y. J, J, J, etc., indicate insulated joints which fix the limits of track circuits concerned in the proper operation of this train operating system. 'I'BB, 'I'BD, TBF and T36 are batteries for track circuits, B, D, F and G respectively.

In Fig. 2, T and RC represent transmitting and receiving equipment for the train carried communicating station. Connected with it is a loop or coil I I5 representing the inductor. Where the head end and the rear end of the train are equipped, both such stations will be of the type indicated in Fig. 2. The inductor H5, which is located on the train, is normally in inductive relationship with the center oi the track conductor, which forms a part of the intermediate circuit. Instead of a coil of several turns, the inductor H5 may be a single conductbr loop. A typeoi' transmitting and receiving set for a train is illustrated in detail in Fig. 10.

Paralleling the stretch of track equipped for this system 01 communication is a selective and communicating circuit, usually referred to as the dispatchers telephone line, which is in reality a part 0! the wayside station equipment already referred to.

That this system of communication may properly meet railway requirements, the arrangement. should be such that there will be a minimum of interference with communication between the head end and rear end of a train, and communication between the dispatcher and the train whenever he considers it necessary.

In general in operating trains over a track district it is necessary for the conductor to give instructions to the englneman. sary for the engineman to give information to the conductor regarding the conduct of the train.

5 conditions ahead of the train, etc. It is also necessary for the dispatcher to give orders to 'the trains, as .when it is desired that one train take a. siding to allow another train to pass, and the like.

In order to glue the flexibility desired and pro:-

vide an eiiicient operating system, a communicating zone or circuit arrangement iscreated, which in reality travels with the train. To provide this traveling zone, a series of intermediate circuits are arranged such that a moving train passes successively from the influence of one intermediate circuit to the 'next, maintaining itself continuously within a communicating zone for both rear end to head end and train to roadside communication.

Generallyspeaklng, for train communication, and especially telephone communication, amplification is necessary for either transmitted or received signals. Amplification of signals in both 15 the sending and receivihg'eouipment are desirable, especially where inductive disturbances are'likely 'to interfere with mummy.

Intermediate circuitsr-The style. and lengthof the intermediate circuit is governed by the 0 density of traiiic and the physical and electrical conditions existing in the irnmediate'vicinlty of the stretchoi equipped track. a I

The communicating zones, or intermediate circuits, may be shorter for a very busy railway than for one just moderately busy. The type of the intermediate circuit" is largely determined by the amount of inductive interference there may be adiacent to the railroad which would hinder proper communication. 'The. intermediate cir- 0 cuit referred'to in Fig. 1, about to be described.

is one which takes into account both density of traflic and inductive interferences. For ease in describing this system, 'the stretch of equipped track is divided into a series of sections, A, B,

Comprising an intermediate circuit is aconductor carriedgon the track, usually in the center '0! the track, a transformer and'a'cmductor-carried on'. a pole line, connected with the conductoron the track. P'I'he pole line conductor is usuallyreferred to as thereturn part oi the circult. Instead of a; conductor on "a pole'line, a conductor'may' be carried along the trackside in conduit; or the track rails may be used as the return Part of the circuit, or .in the case of two-track one conductor may-he in the center of one track and the other in "thecenter of theother track (see Fig. 12); 'I'he transformer is only necessary ,for

'comnmnlcationbetween the train and wayside. Normally the circuits and apparatus are as indicated in 1. Where the track rails are used as the return part of the circuit,,;the rail Joints should lie bonded. If the track already are bonded, due to their usein track circuits, the

tions should bebndsed by re i cesby 0n densers. Either one run or bothrails may 'be used in the return of the circuit. In any case, thegeneraljarrangementg'wo fld be similar I to that shown inapplicant's tic-pending applicati n. Serial No. 227.932.

A typicalintermediate circuit is that for leection O.,which includes conductor I, contact I normally closed, conductor I05. transposition It is also neces- "insulated io'ints'llmlting the track circuit-ceca m. conductor m, and transposition rec. Anadiacent intermediate circuit as that for section E comprises: Conductor lfll, contact Ill! normally closed, conductor I09, transposition TSE, conductor I09, transformer WF, contact llll normally closed, conductor I01 and transposition 'I'SE. It will be noted that although these intermediate circuits are adjacent. each is electrically separate and distinct from the -other.- when a train passes from intermediate circuit C to-intermediate circuit E, it must travel through track section B. While the train is in track section D, relay TD is tie-energized so that contacts I" and iii! are closed on their back points. This throws the intermediate circuit C and E together into one combined circuit which then comprises: conductor I03, contact I normally closed, conductor I05, transposition I'BC. conductor Hi5, back contact I68 closed, conductor lllll. transposition TSE, conductor I09, transformer WF,

front contact H ll normally closed, conductor I01, transposition" 'I'SE, conductor lll'l. contact lllt closed onits back point, conductor Illl, transposition TS C; In thiecombination of the 'two intermediate circuits another transposition of the conductors takes place in that the relay TD being de-energized, the track conductor I05 is connected to line conductor I09, and .track con.- ductor 'lll'l is'connected to line conductor IIII- Income installatlons'the transposition which occurs, when the track relaycontacts are iii-their abnormal state, is sumcient to counteract any detrimentalinductive effects there may be. when two adjacent intermediate circuits are tempo-l rarily combined into one circuit;

When a train enters a passing siding an ar rangement is desirable that communication for intra-train purposes and communication with the dispatcher 'may be maintained;

As shown in 1, there is a separate and distinct intermediate circuit for the siding, which will be referred to as intermediate circuit H. and

only one half of which is shown in the illustration. Normally this intermediate circuit H comprises: conductor I I6, front contact 13 normally closed. transformer WG, front contact 14 normally closed, and line conductor Ill. 'Ifhe other .half of this circuit, corresponding with the other an: of the siding. also not shown, is identical with thatquotedw- "For the main line includingthe track section I .of Fig. 1-, there is another separate and distinct intermediate circuit which-comprises: track conductor I l I front contact I II normally closed; and line conductor I it. The other half of this circuit which is not shown is identical with that quoted,

except the un'shdwn part contains a transformer identical in its connection as that referred to for intermediate circuits CfandE. M

For a train passing through section}, track relay TI is de-enerzized, in turn lie-energizing thatoontacts B and ll aremadeoatheit back points, thus I" to trans 'conductoH l4 to'cbnductor II", and also connecting track conductor Ill! through back contact II with line conductor H8. Therefore, for the period that the train is within the track sections F and G, the three inter mediate circuits for sections H, .I and E. are connected together, substantially'in parallel, and communication facilities, are maintained as the train proceeds. After the train has cleared section F and while it is still in section G, intermediate circuits' E and H are connected together. When the train passes out of section (3 into sec tion H, it is wholly within the zone of intermediate circuit H for communicating purposes. The foregoing explanation of the intermediate circuit arrangement shows how atrain is always within an intermediate circuit which is in continuous communicative relationshipwith the inductors and related parts on the train, creating a zone of communication for the train which travels with the train. This arrangement is, in

effect, what may arbitrarily be considered a traveling intermediate circuit or a traveling communication zone. 1

In the type of intermediate circuit illustrated in Fig. 12, the normal condition of the circuits and apparatus for communication purposes is as indicated. There is shown the complete inter-v mediate circuit for the stretch of track embracing the siding, section Hi, and the main line,

section Ii, and parts of .two intermediate'cir cuits in the main line section El and LI.

Here the conductor is carried down the center of the track for the passing siding and returned in the center of the track for the main line. X

and Y are the track ;rails.' TFl and iIKl are normally de-energized track relays. FX and KK are insulated sections of track. rails long enough so that when a train passes over them they are always occupied by a pair of wheels. WFI and WKI are transformers for connection with the wayside station circuits. 'IB Fl and TBKI are track batteries for energizing track relays TFl and 'I'Kl respectively. TSH is a transposition of the center of track conductors of the siding and the main line. Jl, J l, etc.. are insulated track joints. Ill] is a high voltage power line or other source of inductive eilect. in the immediate vicinity of siding HI. YFI is a selector relay. DI and D2 are conductors'of the dispatcher's telephone and selective system. 408, "3 lllir and llll are conductors of intermediate circuits cated on the track, preferably in the center be-. tween the train rails. SWl-SWI are the track switches leading to the siding. El, Fl, Hl, I l, KI and Li are sections of track of which Fl and Kl are'i'or operating track relays.

For sections El and LI part al the intermediate closed, and conductor J02. The balance of the circuit is identical with that part shown for sectlon Ll which comprises conductor I", back contact I08 normally closed, and conductor: 4. Fixed transpositions will also be made in these. circuits, like TSC of Fig. 1 when In Fig. 12 the intermediate circuit for sections" circuit is on-the trackway, preferably in the center between the track rails, and partls removed wayside circuit, as shown. or automatically ,con-

In this way the conductors of adjacent circuits are connected together in transposed relationship to form a single enlarged intermediate circuit adapted to cooperate with the'trainwhile the train is passing from one section toanother.

With the train in section Kl relay TKI is energized, closing contacts 408 and 406 on their front points and connecting conductor 405 with conductor I01 and conductor 403 with conductor 409. It .will be observed that in this case also the conductors of the adjacent circuits are connected in transposed relationship to'form a single large intermediate circuit in which the inductive disturbances are reduced toa minimum.

Transpositions in intermediate circuits, as TSH, are desirable when inductive disturbances are present of the character which will afiect the operation of the communicating system. Then they are made of a frequency and at locations to best meet the condition existing in the locality.

In Fig. 12 assume a high voltage power line, as conductor llll adjacent the railroad track, which produces inductive effects in the intermediate circuit iorsections HI and I1, transpositions would be made between the conductors I3 and 405 as shown at TSH, of the number and at locations to greatly minimize, it not entirely eliminate, the inductive disturbance. Assume but one transposition will be. necessary in the case of this intermediate circuit, it will be located so .that any inductive disturbance in one loop will balance the inductive disturbance in the other loop, and since they are in opposite directions, one will, destroy the other. For example, if the exposure 01' conductor 4054;) power line H0 is the same as the exposure of conductor to the power line, the induction in each isequal, and since this inductive ellect is in opposite directions in the circuit, as. illustrated by arrows 4H and I2, it will destroy itself.

Transformers WFl and will may be connected in one of severalways to the wayside station conductors DI and D2, or the dispatchers system. Usually transtormer WFl will be connected as shown through the-operation of the selective systemrbut transformer WKI will be preferably either permanently connected to the nected due to the presence of the train on the siding or on the main line between switches SWI, in order to give trains in this intermediate circuit the privilege of initiating communication with the dispatcher. This intermediate circuit Hl-ll may also -be selectively" connected to the dlspatcher's line if desired. In Fig. 1 trans former W6 is arranged to be automatically connected to the waysidc system. conductorspl and D2, by the presence of a train in section B. i

The intermediate circuit for section Ian-+11 P 8. 12 an advantage in that both sides 0! the in teclrcuit-arc available, tor-communication purposes; and it would be adaptable foruseonad o! installation and maintenance would then be proportionally decreased. Also, communication could be carried onbetween a train on the main line and one on the siding, without disturbing the dispatcher, or providing connections through a transformer.

Referring again to Fig. 1, assume intermediate circuits A, C and E and train III of such length that the train at one time occupies all three of said intermediate circuits including the track section circuits B and D. Relays TB and TD being de-energized, their contacts are made on their back points resulting in intermediate circuits for A, C and E being combined in one circuit for such time, such combined circuit comprising,- conductor I00, back contact I04, conductor I05, transposition TSC, conductor I05, back contact I08, conductor I00, transposition TSE, conductor I09, transformer WF, front contact IIO, conductor I0I, transposition TSE, conductor I0'I, back contact I06, conductor I03, transposition 'ISC, conductor I03 and back contact IN to conductor I02. The part of the intermediate circuit A, not shown, which is identical with the left hand section of intermediate circuit C, completes the combined circuit; and transformer WF is adapted for the dispatcher to connect his telephone line, conductors DI and D2, with such combined circuit when he desires to communicate with the train. Two trains running close together might form such combined circuit, onetrain being within track section circuit B and the other in track section circuit D, in which case the trains may communicate with each other.

The wayside station and system.-Located in the wayside station is a transmitting and receiving set T and RS, and a selector operating set SOS (Fig. 1). Each of these sets when in use is connected directly to conductors DI and D2 which extend along the railroad throughout the stretch of equipped track. Connected with the conductors DI and D2 are selector relays YB, YD, YF, I1 and I8. The first three are for the purpose of connecting the dispatchers line, conductors DI and D2, directly with the corresponding intermediate circuits, A, C and E, through the medium 01' transformer WB, WD and WF respectively. Selector relays I1 and I0 are for the purpose of operating the signals governing train movements over the switches as will be later explained. Selector relay YB when operated closes contacts I22 and I25, thus connecting transformer WB with conductors DI and D2 through conductors I2I, I23, I20 and I20 respectively. Selector relay YD when operated closes contacts I30 and I32 thus connecting transformer WD and conductors DI and D2 through conductors I20 and I3I and I32 and I30.

Transformer WF' has three coils, one primary, and two secondary; one secondary is the medium for connecting intermediate circuit E, and the other secondary the medium for connecting intermediate circuit H to the dispatchers line, conductors DI and D2. When selector relay YF is operated, contacts I30 and I30 are closed, connecting the transformer primary coil conductor I35 to conductor I 31, and conductor I30 to conductor I40.

Selector relay YB is connected to dispatchers line, conductors DI and D2, by conductor I I0 and conductor I20 respectively. Selector relay YD is connected to dispatchers line, conductors DI and D2, by conductors I21 and I20 respectively. Selector relay YF is connected to dispatchers line, conductors DI and D2 by conductors I53 and I5! respectively; selector relays II and I8 are connected to dispatchers line, conductors DI and D2,'by conductors I45 and I46 respectively. The circuit for repeater relay FR includes contact I2 normally closed and battery I55.

The selector operating system SOS and the selectors responsive thereto may be of any one of the several well known systems in commercial use as that of the Western Electric, the Gill, or the Sandwich. In these systems a key or switch in the dispatchers ofnce is adapted to send out a code of electrical impulses, there being a diiferent code for each selector. When the dispatcher wishes to operate a particular selector, he connects the code key corresponding to that selector to the conductors DI and D2. When he operates this key a code of impulses is sent out over the conductors DI and D2 and said selector, being energized by these impulses, responds thereto. All other selectors, not being responsive to said impulses, do not function.

The track circuits for section B, D, F, G, etc. of Fig. 1, are of the usual type where the track rails are part of the circuit and a battery located at one end of the section is connected to the track rails, and the relay at the other end of the section is also connected to the track rails. These track relays as shown in Fig. l are normally energized.

When the train is in section H relay TH is deenergized, closing back contacts I5 and I6, connecting conductors I41 with I52 and I49 with I5I respectively, so that transformer W6 is bridged across the dispatchers line, conductors DI and D2, and in this manner the intermediate circuit H is automatically connected to the dispatchers line.

Wayside station transmitting and receiving set T and RS.In Fig. 11 are the details of the transmltting and receiving set in the roadside communication station, which may also be considered as the transmitting and receiving set in the dispatchers oflice.

O2 is a generator for signaling purposes, of the same frequency of electric current as generator Oi in Fig. 10 to give a high pitch note, but of interrupted current to be distinguishable from the signal resulting from the operation of OI. HS2HS4 is a double contact hand switch of the push key type for operating the signaling or calling circuits pertaining to generator 02. Switch arms H32 and HSI are here shown as operating together. SA2 is a switch device for controlling various circuits relating to the transmitting and receiving means, normally held in the position shown by spring 316. T2 is a transmitter. T32 is a source of energy in the transmitting circuit. W2 is a transformer connecting the transmitter circuit with the transmitting amplifying circuit. V2 is a transmitting amplifying tube. A2 and BL2 are sources of energy respectively for filament and plate circuits of tube V2. G2 is the battery for grid of V2.

DI and D2 are the conductors for dispatchers telephone and selective system, or for the roadside communicating station along the track. I92 and I55 are conductors connecting the transmitting and receiving means of the wayside station with the roadside conductors DI and D2.

W4 is a transformer connecting the amplifying transmitter circuit to the circuit leading to conductors DI and D2.

W0 is a transformer connecting the receiving circuits in the wayside station with the wayside conductors DI and D2.

U2 and U0 are amplifying tubes for two stages of amplification in the wayside receiving circuit.

A4 and BL4 are sources of energy respectively for the filaments and plate circuits of tubes U2 and U4. G4 and G6 are the C batteries respectively for the grids of U2 and U4. W8 is a transformer connecting the amplifying circuits of tube U2 with the amplifying circuits of tube U4.

LS2 is a signaling receiving means on the order of a loud speaker, a relay or an alarm responsive to the signals sent out from the sources of energy OI of the train stations; also serving to indicate when generator 02 is operated.

RE2 is a receiver on the order of a loud speaker, or it may be a receiver of the type known as head phones.

Q2 and CID are condensers. the adjustable type.

SC2 is a switch on the order of the ordinary telephone receiver hook. Normally it is closed on contact 362 in the circuit for device LS2. If it supports the receiver RE2, then, when this receiver is removed, contact 358 will automaticall close.

Connected with switch arm SC2, and operable with it, is switch arm SC4. Normally contact 314 is closed to included condenser CID in the circuit of transformer W6. When this switch arm S04 is operated to close contact 312, condenser CID is eliminated from the circuit of transformer W8.

Impedance Z2 is in the circuit of transformer W6 when generator 02 is energized in the circuit of conductors DI and D2, etc. The resistance factor of Z2 is large so that not enough energy passes from generator 02, when the hand switch HS2-HS4 is closed, to transformerWG to overload the amplifiers. The inductance factor of the circuit which includes impedance Z2 is preferably equivalent to the capacity factor of the circuit including CID. Instead of being an impedance, Z2 may be a resistance. The inductive reactance of the circuit, particularly as regards transformer W6, may be objectionally high. Therefore, the function of condenser CID is to equalize the inductive reactance of the circuit to the extent that the signal received as an indication of the proper operation of the generator 02 may be distinct and undistorted.

R2182 and RES4 are variable resistances controlling the filament currents of tubes VI and UI and U3 respectively.

Circuit for the wayside station transmitting signaling means.-The transmitting signaling means 15 provided for the purpose of calling an attendant on the train by a signal of distinctive character to answer the phone. The circuit (Fig. 11) comprises switch arm H82, normally open contact 332, conductors I56 and D2, one of the intermediate circuit transformers as WD. depending upon which one is connected by a selector relay, or otherwise, conductors DI, I92 and 334, condenser Q2, generator 02, conductor 303, normally closed contact 306 and conductor 382. When switch H82 is operated contact 332 closes and the circuit is energized. The condenser Q2 is for the purpose of making the circuit resonant, or nearly so, to the frequency of the generator 02.

Associated with the transmitting signaling, or calling means, is a means for determining whether the signaling impulses are actually produced by the generator 02. When switch HS2-HS4 is operated contact 318 is opene disconnecting the primary receiving circuit of transformer W6 from its direct connection with conductor I92, and contacts 332 and 380 are closed placing gen- Either may be of erator O2 in circuit with transformer W6 as follows: generator 02, conductor 384, impedance Z2, contact 380, switch arm HS4, conductor 33D, contact 328A, conductor 32B, transformer primary W6, conductors 326 and 316, condenser CID, contact 314 closed, switch arm S04, conductor 3"), contact 332, switch arm H52, conductor 382, contact 306 and conductor 308.

Circuits for transmitting communications from the wayside.-Normally the transmitting circuits of station T and RS are open. When it is desired to transmit a communication (Fig. 11) switch SA2 is operated against the force of spring 316 closing contacts 3I8, 304A and 335A and opening contacts 328A, 366A and 305.

The transmitter circuit comprises transmitter T2, conductor 802, transformer primary W2,

battery TB2, contact 304A closed only when switch 8A2 is reversed, and conductor 304.

The communicating impulses set up in the transmitter circuitare induced through transformer W2, into the transmitting amplifying means, the circuits for which comprise:

Grid of tube V2, conductor 31D, transformer secondary W2, battery G2, and conductors (H2 and 322. The filament circuit of tube V2 includes battery A2, conductor 3I6, contact 3I8 closed when switch 5A2 is reversed, conductor 32D, adjustab1e resistance RES2, filament of tube V2 and conductors 322 and 3I2. In the plate circuit of tube V2 are battery BL2, transformer primary W4, and conductor 324.

The amplified transmitted impulses are induced through transformer W4 into the wayside circuit including conductor 336, contact 336A closed when SA2 is reversed, conductors 386, I92 and DI, the intermediate circuit transformer which may be connected to conductors DI and D2, conductors D2 and I56 and secondary of transformer W4.

Circuits for receiving in the wayside station.- Normally the receiving circuits of station T and RS are closed as illustrated in Fig. 11. It is considered good practice in this system to open them when communications are being transmitted from the same station. The primary receiving circuit for signaling comprises conductors DI and I92, contact 318, conductor 33D, switch 328A normally closed, conductor 328, transformer primary W6, conductors 326 and 31D, condenser CID, contact 314, switch arm S04, and conductors 3M, i56 and D20 Whichever transformer in an intermediate circuit is connected to conductors DI and D2, completes this primary receiving circuit. The condenser CID is for the purpose of making the calling primary receiving circuit resonant, or nearly so, to the frequency of the signaling current.

The primary receiving circuit for communications in the wayside station is the same as the primary receiving circuit for signaling, just described, except that part of the circuit connecting between conductors 326 and 3ID includes contact 312 closed, instead of contact 314, and condenser CID is eliminated from the circuit.

At transformer W6 the received signaling and communicating impulses are carried to the receiver amplifier the circuits for which comprise:

For the grid of tube U2, conductor 346, transformer secondary W5, battery G4 and conductor 338 and 340 to filament of U2.

The filaments of tubes U2 and U4 are connected in parallel by conductors 342 and 344 and to a source of energy A4 by the circuit including adjustable resistance RES4, conductor 356, contact 336A normally closed, and conductor 368.

The plate circuit of tube U2 includes conductor 343, transformer primary W3, conductor 353. and battery BLI.

The grid circuit of tube Ul includes conductor 352, transformer secondary W3, battery G6 and conductor 342.

For the amplified received call signals the plate circuit of tube U4 includes battery BL, conductors 350 and 353, signaling means LS2, contact 382 normally closed, switch 802, and conductor 364.

For the amplified received communication signals, the plate circuit of tube U4 includes battery BLI, conductors 350 and 354, receiver RE2, conductor 356, contact 353 closed, switch 802, and conductor 3.

Train carried stations.-Fig. 2 shows a transmitting and receiving communication set T and RC on the train. This is connected to a loop or cell comprising inductor I I5 for both transmitting and receiving. Inductor H5 is located on the train to be inductively associated with that conductor of the intermediate circuit which is located on the track; for example, with a train in section C, Fig, l, inductor I I5 is located to be within the proximity of track conductor "13 or ll|5 so that any transmitting current influence in inductor I I5 will be inductively received in conductor I33 or I05. and thus into the intermediate circuit. Conversely any current influence in the intermediate circuit will be transmitted from conductor I03 or I05 to inductor H5 and thus be received in the receiver on the train. Instead of a coil of several turns the inductor H5 may be a single conductor loop.

When there are two communicating stations on the train, both will be the same as the one described, and each will be in the same relationship with the track conductor of the intermediate circuit.

Train transmitting and receiving set T and RC'.In Fig. 10 is shown the details of the transmitting and receiving set in the train station, or in the train stations when both ends of the train are equipped.

OI is a generator for signaling purposes preferably or a prescribed electric current output of a frequency giving a high pitch note. HSl-HS3 is a double contact hand switch, of the push key type for operating the signaling or calling circuits pertaining to generator Switch arms RSI-H83 are here shown as operating together.

I I is an inductor which is here shown as of the loop or single conductor type. It may also be of a coil type, consisting 01' several turns of a conductor, or it may be of an electromagnetic type comprising a coil with an iron core.

SAI is a switch device for controlling the various circuits relating to the transmitting and receiving means. 315 is a spring holding switch SAI in the normal position. TI is a transmitter. TBI is a source of energy in the transmitting circuit. WI is a transformer connecting the transmitter circuit with the transmitter amplifier. VI is a. vacuum tube, amplifying the transmitted signals. AI and BLI are respectively the filament and plate sources of energy for transmitting tube VI. GI is the C battery for grid of VI. Transformer W3 connects the amplified energy with the circuit oi inductor I I5.

W5 is a transformer connecting the receiving means with the inductor H5. UI and U3 are vacuum tubes for two stages of amplification of the received signals, A3 and BL3 are sources of energy respectively for the filament and plates of the tubes UI and U3. G3 and G5 are the C batteries respectively for the grids of UI and U3. W1 is a transformer connecting between stages of amplifier UI and U3. LSI maybe a loud speaker, or it may be a relay or some other device which'is responsive to certain signals as those emanating from generator OI, or from generator 02 of the wayside station. REI is a receiving instrument. It may be a loud speaker or it may be of the head type of receiver.

QI and C9 are condensers, either may be of the adjustable type.

SCI is a switch on the order of the ordinary telephone receiver hook. Normally it closes the contact 36I in the circuit for device LSI. If it normally supports receiver REI, then the removal of this receiver automatically closes contact 351. Connected with switch arm SCI, and operable with it, is switch arm S03. Normally contact 313 is closed to include condenser C9 in the circuit of transformer W5. When this switch arm SC3 is operated to close contact 31I, condenser C3 is eliminated from the circuit of transformer W5.

Impedance Z! is in the circuit of transformer W5 when generator OI is energized in the circuit of inductor H5. The resistance factor of Zl is large so that not enough energy passes from generator Oi, when the hand switch HSI-HS3 is closed, to transformer W5 to overload the amplifiers. The inductance factor of the circuit which includes impedance ZI is preferably equivalent to the capacity factor of the circuit including condenser C3. Instead of being an impedance, ZI may be a resistance. The inductive reactance of the circuit, particularly as regards transformer W5, may be objectionally high. Therefore, the function of condenser C9 is to equalize the inductive reactance of the circuit to the extent that the signal received as an indication of the proper operation of the generator may be distinct and undistorted.

RESI and RES3 are variable resistances controlling the fllament currents of tubes VI and UI and U3 respectively.

Circuit for the train transmitting signal means.This signaling means is provided for the purpose of calling the attendant on the other end of the train, or the dispatcher when he is called, to answer the phone. Its circuit comprises switch arm HSI, contact 33I, closed when HSI is operated, conductor 303, inductor I I5, conductor 333, condenser QI generator OI conductor 301 and normally closed contact 335. When switch arm HSI is operated, contact 33I is closed and the circuit is energized. The condenser QI is for the purpose oi. making the circuit resonant, or nearly so, to the frequency of the generators OI and 02.

Associated with the transmitting signaling or calling means is a means for determining whether the signaling impulses are actually produced by the generator OI. When switch HSI-HS3 is operated, contact 311 is opened, disconnecting the primary receiving circuit of transformer W5 from its direct connection with conductor 333, and contacts 33l and 319 are closed, placing generator OI in circuit with transformer W5 as follows: generator 01, conductor 383, impedance ZI, contact 313, switch arm HS3, conductor 329, contact 321A, conductor 321, transformer primary W5, conductors 325 and 315, condenser C9, contact 313 closed, switch arm SC3, conductor 3119, contact 33I, switch arm HSI, contact 335 and conductor 301.

Circuits for transmitting communications from the train.-Normally the transmitting circuits of Fig. 10 are open. When it is desired to transmit a communication from a train station, switch SAI is operated against the force of spring 315, closing contacts 3I1, 303A and 335A, and opening contacts 321A, 365A and 305. The transmitter circuit comprises transmitter TI, conductor 3M, transformer primary WI, battery TBI, contact 303A closed only when switch SAI is reversed, and conductor 303.

The communication impulses set up in the transmitter circuit are induced through transformer WI into the transmitting amplifying means, the circuits for which comprise:

Grid of tube VI, conductor 333, transformer secondary Wi, battery GI, conductors 3H and 32I. The filament circuit of tube VI includes battery AI, conductor 3I5, contact 3I1 closed when switch SAI is reversed, conductor 3H, adjustable resistance RESI, filament of tube VI and conductors 32I, 3H and M3. In the plate circuit oi tube VI are conductor 323, transformer primary W3, and battery BLI.

The amplified transmitted impulses are induced through transformer W3 into the inductor circuit which includes conductor 335, contact 335A closed when SA! is reversed, conductors 385 and 333, inductor H5, conductor 303 and transformer secondary W3.

Circuits for receiving in a train stati0n.-Normolly the receiving circuits of train station T and RC are closed, as illustrated in Fig. 10. It is considered good practice in this system to open them only when communications are being transmitted from the same station. The primary receiving circuit for signaling comprises inductor H5, conductor 303, switch arm S03, contact 313, condenser C3, conductors 315 and 325, transformer primary W5, conductor 321, contact 321A normally closed, conductor 329, switch arm HS3, contact 311 and conductor 333.. The condenser C3 is for the purpose of making the calling primary receiving circuit resonant, or nearly so, to the frequency of the signaling current.

The primary receiving circuit for communications in a train station is the same as the primary receiving circuit for signaling, just described, except that part of the circuit connecting between conductor 325 and 339 includes contact 31I closed, instead of contact 313, and condenser C3 is eliminated from the circuit.

At transformer W5 of Fig. the receiving signaling and communicating impulses are carried to the receiver amplifier, the circuits for which comprise:

For the grid of tube UI, conductor 345, transformer secondary W5, battery G3, and conductors 331 and 333 to filament of UI.

The filament of the tubes UI and U3 are connected in parallel by conductors 3 and 343, and to a source of energy A3 by a circuit including adjustable resistance RES3, conductor 365. contact 355A normally closed, and conductor 361.

The plate circuit of tube UI includes conductor 341, transformer primary W1, conductor 343 and battery 3L3.

The grid circuit of tube U3 includes conductor 35I, transformer secondary W1, battery G5 and conductor 34L For the amplified received call signals, the plate circuit of tube U3 includes conductor 3B3, switch SCI, contact 33I closed, signaling receiving means LSI, conductors 353 and 343 and battery 3L3.

For the amplified received communication signals, the plate circuit includes conductor 333, switch arm SCI, contact 351 closed, conductor 355, receiver REI, conductors 353 and 343 and battery BL3.

Switch and signal operating meana-A feature of the general system of train operation which is comprised in this invention is that of means permitting trains to enter and leave passing sidings and diverging routes. The arrangement is such that normally the passing siding switch is set for the movement of trains along the main line. In the case where a train is to take a siding, a circuit controlling device may be operated, controlled either from the roadside, by the dispatcher, or the train, which will operate the track switch for train movements from the main line into the siding. When the track switch starts to operate, the signals governing train movements over the switch on the main line, will be set at stop. When the track switch is operated to the reverse or open position and is properly locked, signals governing train movements to and from the siding will indicate showing that the route is properly set for the train to proceed. Upon the train proceeding from the main line into the siding and clearing the fouling point of the siding with the main line, the track switch will automatically return to the main line position. Since the operating mechanism is joined to the track switch through a spring connection, it is feasible for a train on the siding to come out on the main line regardless of the position of the points of the track switch. Should the track switch be set for the main line and the train come off the siding, the points will be crowded over by the flanges of the wheels of the train against the tension of the spring connection, and the train will proceed without being damaged or without damaging the points of the switch.

When a train passes over a track switch in a direction facing the points, locking means are provided by which automatically the switch is locked in position, so that the points cannot be moved during the time the train is passing over them. This locking means, as will be hereafter shown, is not operative to lock the points of the track switch when the train passes over same trailing.

It is desirable when the train dispatcher gives an order to the train to take a passing siding, that he be able to check the observance of the order by causing the signals at the track switch to be at stop so as to protect trains, one on or about to take a siding and an another on the main line, against collision with each other.

In Fig. 3 the various track sections, signals, track relays, power switch mechanism, and the like, are the same features as referred to in Fig. 1, with the same symbols for each. HS is a circuit controlling device located on the roadside in such a position that it may be operated by hand from a passing train, or it may be operated manually by an attendant on the ground. or by the dispatcher from a distance, or it may be operated by contact or inductive means from the train. Normally circuit controlling device HS is held in a non-contacting position by the spring 80. RI is a relay for operating the track switch from the normal to the reverse position. R2 is a relay for controlling the operation of the track switch from the reverse to the normal position and it operates automatically. Ml, M2 and ML are electromagnetic means controlling the operation of the power mechanisms SM and SL.

ICI, LC2, LC3, and DC are circuit controllers normally closed and open as shown, and which have the opposite positions during the interval that the lock plunger LP is withdrawn from the control rod 61. tacts controlling signals 82 and 83 respectively, and operated by selector relay Ti. H is a contact controlled by selector relay III in the circuit of signal S4. 58 is a contact operative from the facing point lock connecting means, rod 84, (Fig. 4) being normally closed, but open when the plunger 55 is engaged with the facing point lock FPL and control rod IBI. -'l2, 13, II. 15 and 16 are identical with similar contacts shown in Fig. 1 for operating the communicating means. Selector relays I1 and I8 are identical with the similarly' numbered selector relays shown in Fig. 1.

FLB is the operating feature of the facing point lock FPL which together with connected rod 64 is referred to in detail in Figs. 4 and 5.

TF is a relay for the track circuit section F which includes that portion of the main line in which switch SW is located. TG is the relay.

for the track circuit section G in the siding between the connection of the siding with the main line and about the clearance point of the siding with the main line.

S00 is a switch circuit controller connected with, to operate with, the switch SW by the rod I98 (Fig. 4). It contains the electrical contacts CI, C2, C3, C4, C5 and C5 which are made and broken as illustrated by Fig. 9.

Circuit for relay RL-This relay controls the operation of the track switch from the normal or closed position to the reverse or open position, and comprises common wire CC. contact 19 of circuit controlling device HS closed, conductor I, back contact 2 closed. conductor 3. coll relay RI, conductor 4. contact CI closed, conductor 5, battery BY, conductor 6 and common conductor CC. As contact CI opens with the switch points moving from the normal to the reverse position, when about one half or three fifths of the stroke of the track switch is completed, another circuit is provided to by-pass contact CI, which circuit includes conductor 9, contact L04 closed, conductor 2i, and conductor 5. Contact LCfl closes at the moment the lock plunger LP is withdrawn from the control rod 67, as will be hereinafter explained, and remains closed until the lock plunger LP again locks the control rod 51.

Circuit for lock magnet 1;.L.Lock magnet ML controls the admission of air or fluid into cylinder SL for the withdrawing of lock plunger LP from the control rod 51. The circuit for the lock magnet ML comprises conductor 6, battery BY, conductors 5, 2i and I0, contact II normally closed, conductor I2, coil ML, conductor l3, contact C5 closed with the switch in its normal position, conductor I4, contact I5 closed only when relay RI is energized, and conductors IS, IT and common CC. When the switch is in the reverse position, contact C5 is open and contact C6 is closed, the circuit then being from conductor I3 via contact C6, conductor I8, contact I9 closed only when relay R2 is energized, and conductors 20, I1 and common CC.

Circuit for lock: magnet M1.This includes conductor 6, battery BY, conductors 5 and 2I, contact LC2 closed, conductor 22, contact 23 normally closed, conductor 24, coil magnet MI, conductor 25, contact 26 closed, and conductors 21, lid and CC.

56 and 49 are selector relay con- Circuit for lock magnet M2.This includes conductor 5, battery BY, conductors 5 and 2I, contact LC2 closed, conductor 22, contact 23 normally closed, conductors 24 and 31, coil magnet M2, conductor 38, contact 39 closed, and conductors 40, I1 and CC.

Circuit for relay R2.-This relay controls the operation of the track switch from the reverse to the normal position and operates automatically after the train has passed over the switch, and while the train is in track section G. This circuit includes common conductor CC, contact 28 closed on its back point, conductor 30, contact 3| normally closed on its back point, conductor 32, coil relay R2, conductor 33, contact 34 normally closed, conductor 35. contact C2 closed when the track switch is reversed, conductors 35 and 5, battery BY and conductor 6.

As contact 02 opens before the switch has entirely completed its stroke in moving from reverse to normal position, a bypass circuit for this contact, when open, is provided, which includes conductor 29, contact L03 which is closed when the track switch is unlocked and conductors 2| and 5.

Circuit for signal S3.'I'his signal governs train movements over the switch along the main line. Its circuit comprises common conductor CC, contact AI, normally closed, conductor 62, contact LCI normally closed, conductor 44, contact 45 normally closed. conductor 46, control mechanism signal 83, conductor 41, contact C3 closed when the switch SW is normal, conductor 48, contact I normally closed and conductor 49a, leading on through block to battery and common conductor.

Circuit for signal S1 .-This signal governs train movements from the main line into the siding. Its circuit comprises common conductor CC, contact 4| normally closed, conductor 42, contact LCI normally closed, conductor 54, contact 45 normally closed, conductor B6, control mechanism signal SI, conductor 50, contact C4 closed when the switch SW is reversed, conductors 5I and 5, battery BY and conductor 5 to common conductor CC.

Circuit for signal S2.--This signal governs along the main line over the track switch for trailing train movements. Its circuit comprises common conductor CC, contact 52 normally closed, conductors 53 and 55, control mechanism signal S2, conductor 55, circuit controller 56 normally closed, conductor 51, contact 58 normally closed, conductor 59, contact 60 normally closed, and conductor 6| through the block to battery and to commonconductor CC.

Circuit for signal S4.--This signal governs train movements from the siding to the main line and through the block. Its circuit comprises common conductor CC, contact 52 normally closed, conductors 53 and 69, control mechanism signal S4, conductor III, contact Ii normally closed, conductor 51, contact 58 normally closed, conductor 59, contact 60 normally closed and conductor BI, through the block to battery and common conductor CC.

Locking device for train movements facing the track: switch-In Fig. 4 X and Y are the track rails, and I and I9I the points of switch SW shown in normal position. Bar FLB is the main operating feature of the facing point switch locking and unlocking means, and is connected with rod 6| by rocking shafts 83 and arms I and I15; and rod 64 is connected to facing point lock plunger 65. BB is the spring-butler means joining the power mechanism SM to switch points I99 and I9I. SCC is a switch circuit controller connected by rod I98 with the switch SW at lug I14. Ill and I59 are the levers of the dual switch stand I49. Rod I1! is for connecting stand I49 with the switch SW. Rod I19 connects lever I59 with the power mechanism SL for unlocking rod 61'. I91 is a circuit controller which comprises contacts LCI, L02, LC! and LC, (Fig. 3). I15 are bearings supported on the track ties for holding rocking shafts 63. DN and DSare direction arrows for convenient use in the description.

Since a spring and buffer SB joins the power mechanism SM to the switch points I9I and I99 the points are held against the stock rails Y and X under pressure from the spring for the respective reverse and normal positions of the switch. Because of this fact some railway operating men are apprehensive that with trains passing over the switch facing the points something may happen to cause the points to open under the train, resulting in a derailment. It is to obviate any such occurrence that locking means about to be described are provided.

FLB is a bar on the order of a channel, two or three inches wide, with top normally about level with the top of the rail and free to move up and down with a circular motion against the ball of the rail when engaged by the flange of a passing car wheel. This bar is of such length as to always be engaged by one or more wheels of a passing train.

Fig. 5 is a view through the track along the section line KK. The bar FLB is held in the extreme upright position by springs I99. It is free to move with a rotating motion because of the arms I95. A pin I94 is fastened to the bar FLB, and arms I95 at one end of-rocking shafts i3 rotatably connect between the pins I94 and rocking shafts 63. This type of mounting permits the bar FLB to move forward or backward as indicated by positions b and a of arms I95. The other end of the rocking shafts B9 terminates in arms I16 which are pivotally connected to rod 94. The rocking shafts are free to rotate in bearings I15.

Associated with the control rod III for the switch is a facing point lock casting I of the usual well known type. In the control rod I8I are two holes or notches, one corresponding to the normal position of the switch, and the other corresponding to the reverse position of the switch. Plunger 65, under certain conditions to be explained, will enter the holes or notches in rod Ilil, thereby locking the points of the switch against movement. I11 is a fixture rigidly fastened to a tie, through which the lock plunger 95 is free to pass. Rigidly connected to lock plunger 65, but adjustable as to location on said plunger, are collars I18. Also over said plunger 65, but under balanced tension between said collars I19 and said fixture I11, are springs I19. A function of these springs is to normally withhold the lock plunger from the holes or recesses in control rod Ill; 9. further function of these springs I19 is to hold the bar FLB in an upright position with the arms I 9 in a central vertical position.

The ends of the bar FLB are inclined down slightly for a distance of about one or two feet, so that when struck by the flange of a. passing wheel, there will be less shock, and the tendency will be for the bar to move in the direction of the movement of the train.

When a train is moving facing the switch (direction DS) the flanges of the wheels force bar FLB, forward, holding it in a position corresponding to position b of the arms I95, due to the pressure of the flanges on the top of said bar, as long as there are wheels over the bar. When bar FLB is moved as just indicated, the rocking shafts 63 are operated to cause bar 64 to also move to position b, which forces the lock plunger 65 through a hole in control rod IBi corresponding to the position of the switch. The lock plunger is held in such position until the last pair of wheels has passed off bar FLB, after which bar FLB, due to the pressure exerted by springs I19 and I96, returns to its normal position, unlocking control rod I8I.

In the case of a train moving over the switch SW trailing the points (direction DN) of said switch, the wheel flanges again contact with bar FLB, forcing it to a position corresponding with the position a of rocker arms I95. This causes the rocking shafts to move, and since rod 64 is connected with the rocking shafts, it must move in a direction corresponding to bar FLB, which movement draws the locking plunger 65 further from the control rod IBI, thus leavingsame unlocked for such trailing train movement. It is readily seen, therefore, that when a train trails .through the switch under conditions where the switch is not properly set for such movement, the flanges of the wheels are free to force the switch points over without damaging same or without damaging the train.

For movements of the train trailing the switch, where the position of the switch does not correspond with the route of the train, after the switch points are forced over by the wheel flanges, said points will return to their normal position, due to the spring tension in device SB; and the buffer action, in device SB also permits such return slowly and without shock and damage to the switch points.

Power operated switch mechanism-The type of switch mechanism illustrated in Fig. 4 and in detail of Figs. 6, 7 and 8, is intended for operation by air or by some hy draulic medium as oil or a combination of the two. It consists essentially of an operating cylinder SM and a locking cylinder SL.

69 is the head rod connection for the switch. It is connected by control rod I91 with springbufler mechanism SB, which in turn is connected by rod 66 with the piston of power mechanism SM. The rod 61 which is primarily for the looking means is also connected with the piston of power mechanism SM. In the rod 91 are holes or notches, NP and RP, (Fig. 8) corresponding respectively with the normal position and the reverse position of the switch SW.

The power mechanism SM is shown in detail in Fig. 6, the same being a cross section through the length of the mechanism SM on a center line of the connecting rods 91 and 66. 252 is a piston in the cylinder of SMand is rigidly connected to rods 96 and 61.

Admission of air or fluid into the cylinder of SM for operating piston is controlled by electromagnetic valves MI and M2. These valves are identical in structure and action, therefore but one will be described.

Valve MI consists of the following parts:

There is an electromagnet which comprises the magnetic core 2", the coil 229, and an enclosing shell. 2|! ls an armature for this electromagnet, held in an upright position by the tension in the spring I. 222 is a valve closing device which normally closes the port 228 at its lower end. The admission of air or fluid under pressure is from a source connected with opening 234; therefore this pressure against part 232 normally keeps port 228 closed. Normally chamber 238 is connected to exhaust port 224 through channels 230 and 228 and chamber 225. The connections to the electromagnet are conductors 24 and 25 which are also shown as a part of the circuit in Fig. 3.

When valve device MI is operated through the energizing of the electromagnet. armature 212 is attracted to core 2!!! against the tension of the spring 214. This causes the stem 2l5 which is rigidly connected to armature M2 to bear down on valve device 222 closing the upper part of channel 228 and opening the lower part of said channel so that air or fluid under pressure is admitted from source opening 234 through channels 228 and 230 into chamber 236. The consequent pressure on piston 252 forces same to the other end of the cylinder, thus moving the switch SW from the normal to the reverse or open position. Chamber 231 is normally open to exhaust through port 225 via channels 23! and 229 and chamber 221 similarly as described for chamber 238.

The operation of the mechanism in moving the switch SW from reverse to normal or closed position is similar to that already described for opening the switch in that air or fluid is admittcd into chamber 231 through source opening 235 forcing-the piston 252 back to its normal position at the other end of the cylinder.

After the switch points are moved to one or the other position, they must be locked in place, which locking is accomplished by the device SL. This is shown in detail in Fig. 7. 253 is a cylinder containing a piston 240 rigidly connected to a piston rod LP. Normally the piston 240 cccupies the position indicated in cylinder 253. It is held in that position by the tension exerted from spring 239.-

ML of Fig. '7 is an electromagnetic valve of exactly the same structure as electromagnetic valve MI. When electromagnetic valve ML is operated, air or fluid is admitted from a source of supply under pressure connected with opening 250. Normally this pressure holds valve 248 to close channel 245 at its lower end. Normally also chamber 25] is connected to exhaust port 245 through channels 249 and 246. Upon the operation of electromagnetic valve ML, valve 248 closes channel 245 at the top, and opens same at the bottom, so that the air or fluid under pressure then flows into chamber 25! through channels 246 and 249. This pressure forces the piston 240 against the tension of the spring 239 withdrawing the lock plunger LP from the control rod 51.

Control rod 51 contains two holes or recesses NP and RP respectively, corresponding with the normal andreverse positions of the switch SW, the same as indicated in Fig. 8. When the switch is moved to one position or the other, lock plunger LP locks the control rod 61 because of the force of the spring 239. The unlocking is always done by the power means described.

The structure I 91 Fig. 4 shelters the circuit controller contacts LCI. LC2, LC3 and LC4 of Fig. 3. When the power means are applied to unlock the switch, the withdrawal of the plunger LP from the rod 51 operates the circuit controller contacts in device I91 to open contact LC! and close contacts LC2, LC! and LC4; these circuit contacts are maintained in this operated condition during the period plunger LP is withdrawn from control rod 41, even though the power may be cut of! and the tension of spring 239 forces piston 245 back for LP to abut on control rod 51;

Referring to Fig. 9. ordinarily the switch points have stroke oi 5". Contacts Cl, C3 and C5 are closed in the normal position of the switch, CI opening about C2 about 345 and C5 about V5 of the stroke of the switch from normal to reverse position and closing at the same points in the return of the switch from reverse to normal. Contacts C2, C4 and CS are closed in the reverse, or open, position of the switch. They open and close in the movement of the switch from reverse to normal and normal to reverse respectively in a manner similar to that explained for contacts Cl, CI and C5.

Switch stand control.Where the track switch is remotely controlled or where it may be controlled irom an approaching train, it is desirable that an arrangement be made by which the switch may be moved by manual means and especially providing something occurs making the power means inoperative.

I48 (Fig. 4) is a switch stand, normally disconnected from connecting rod H2 which is fastened to switch rod 58. Levers I50 and ill are normally in the position shown. Lever ill cannot be operated until lever I50 has been operated. Connecting between lever I50 and locking device SL is rod I12 which ends in an arm 2 (Fig. 7) on the end of which is a roller 2lll. When lever IN is thrown over to the opposite position, two things are accomplished: lock plunger LP is withdrawn from control rod 51 and lever I'll is connected to control rod "2. When lever I50 is V thrown to the opposite position in withdrawing the lock plunger LP, roller 2) moves against part 238 which is rigidly connected with lock plunger LP, forcing same in the direction U, until the extreme limit of travel of roller 2 l 0 is reached, which is the position for arm 2 as indicated by dotted line 254. As the switch is unlocked, lever ill is connected to control rod I12. Lever Ill may now be operated to open and close the switch. It will be observed that the unlocking of control rod 51 by the switch stand lever I50 also causes the circuit controllers LCl, LC2, L03

and LCI to be operated the same as if the control rod 51 was unlocked by the power means described.

The operation of the switch by the hand lever "I also causes the circuit contacts of the controller SCC to be operated, the same as if the switch was operated by the power means.

Operation-Assume a freight train H1 in the section C of a stretch 01' track (Fig. 1) proceeding in the direction indicated by the arrow DS, and that it is necessary for this train Ill to enter the siding to pass another train (not shown) proceeding toward it. The latter train will keep the main line between the switches SW of the passing siding.

Communication between dispatcher and train.The dispatcher operates his selective operating set SOS to energize selector relay YD closing contacts I30 and Ill. This connects transformer WD to conductors DI and D2. He then operates switch 1182-4184 (Fig. 11) opening contact 3 18 and closing contacts 322 and see. This completes the circuit for the Way-side transmitting signaling means already described, including transformer WD. Interrupted electric current impulses from generator 02 are induced into intermediate circuit 0 through the trans former WD. Since inductor H5 is in inductive relation with conductors I 03 and I05 of the in termediate circuit C, heretofore described, as the train proceeds through section C, the distinctive electric impulses from generator 02 are reinduced from intermediate circuit C into the circuit of inductor II5 which is normally closed on the receiving equipment of the set T and RC n the train. it there are two sets on the train, one on the head end and one on the rear end, both receiving sets will receive the signaling impulses from generator 02. These impulses, on being received in inductor I I5, are carried through transformer W to the receiver amplifying means, including first stage tube UI and second stage tube U3, and then to the loud speaker or device LSI, which reproduces as a signal of distinctive character, these electric impulses which the dispatcher has sent out and intends to be received on the train, notifying the attendants on the train that the dispatcher desires to communicate with them.

Through the means associated with the transmitting of the calling means, already described under Circuit for the wayside transmitting signaling means", the dispatcher is advised that the signaling impulses are actually produced by the generator 02.

Assume that the device LSI receives the signaling code only; the train attendant, on hearing the dispatchers call, removes receiver REI from switch arm SCI, which operation breaks contacts 36I and 313 and closes contacts 361 and SH, and operates switch SAI to close contacts 335A, 303A and 3I1. The attendant then talks into transmitter TI, energizing the Circuits for transmitting communication from the train, advising the dispatcher that he is ready to receive o'rders and instructions. The voice currents in the inductor I I5, are reinduced into the conductors I03 and I05 oi'the intermediate circuit C, already described, energizing transformer WD. These voice current impulses pass through transformer WD into conductors DI and D2 and the Circuits for receiving in the wayside station", or dispatchers oi'iice. It may be further assumed that in the meantime the dispatcher has operated switch arm SCI-S06 to close contact 358 and 312. He then receives the communication from the train in receiver RE2.

The attendant on the train after answering the dispatcher's call restores switch SAI to its normal position. The dispatcher, on hearing the answer from the train, operates switch 8A2 to close contacts 336A, 304A and SIB and talks into the transmitter T2 giving the attendant instructions for train 'I I6 to enter the passing siding to allow the other train to pass. Communicating impulses for these instructions pass through the "Circuits for transmitting communications from the wayside", including transformer WD into the intermediate circuit C including conductors III and I05. Here they are re-induced into inductor Iii of receiving set T and RC and' pass through Circuits for receiving in a train station to be reproduced in receiver REI.

On receiving the instructions, the attendant on the train repeats them back to the dispatcher, and in so doing he first operates switch SAI to close contact 335A, 303A and 3". The signals in repeating the instructions pass through the Circuits for transmitting communications from the train. thence through the intermediate circuit 0! C and transformer WD to the roadside system including conductors DI and D2 and the Circuits for receiving in the wayside station."

Signals S2 and 83 set at stop by dispatcher.- In order to check against any misunderstanding of the instructions given a train, the dispatcher sets at stop, signals S2 and S3 which govern trains over the switch SW. The signal S2 will stop the train which is bound in the direction DN between the switches of the siding. The train I" will be stopped at the signal S3 should it attempt to pass same before the switch SW is operated to divert said train into the siding. The operation of signals S2 and S3 to cause them to indicate stop is brought about by the dispatcher operating the selective operating set SOS in his oflice to energize selector relay 11 which opens the contacts 56 and 69 in the circuits of signals S2 and S3 already described as Circuit for signal S2", and Circuit for signal 83'.

Com munication between conductor and engineman.Assuming there are two communicating sets on the train, one in the locomotive on the head end and one in the caboose on the rear end, each as illustrated in Figs. 2 and 10, the train conductor in the caboose will now communicate with the engineman in the locomotive to satisfy himself that the engineman has received and understands the orders and instructions of the dispatcher with regard to the train entering the siding.

In this communication the train conductor operates the switch HSI-HSJI, to open contact 311 and close contacts WI and 319 to connect generator OI on inductor II5 as per "Circuits for the train transmitting signal means. In turn the intermediate circuit C is energized by inductor Iii of the caboose through conductors I03 and I05. Inductor IIII on the forward end of the train picks up the electromagnetic impulses, from the communicating current circulating in the intermediate circuit C. through conductors I03 and I05 and these impulses are carried through the Circuits for receiving in a train stationfibeing received in device LSI of receiving set T and BC on the locomotive.

In acknowledging the call the engineman may now operate switch HSI-HS3 of the set T and ,RC on the locomotive to close the circuit of generator OI, sending electric impulses back through the system as just described, to the caboose where this answering signal is received by the device LSI on the rear 01' the train.

Through the means associated with the transmitting oi the calling means in the sets T and RC on each end oi the train, already described. under Circuit for the wayside transmitting signaling means", both the conductor in the caboose and the engineman in the locomotive cab are advised that the signaling impulses are actually produced by the respective generators OI on each end of the train.

On receiving the enginemans answering signal, the conductor operates switch SAI, to close contacts 335A, 303A and 3H, and talks into transmitter TI. The electric impulses of this communication energize the Circuits for transmitting communications from the train, and inductor IIB of the caboose energizes intermediate circuit C which re-induces the communicating impulses into the inductor III and the Circuits for receiving in a train station 01' the set T and RC on the-locomotive, the engineman in the meantime having closed contacts 351 and I" of the switch arms SCI-8C3. In this communication it may be assumed the conductor has instructed the engineman to enter the siding at the switch SW, and to operate the switch SW as the train approaches the siding. Should the engineman reply to the conductor he will reply in a like manner as already described.

Operation of track switch SW.-On the train approaching the passing siding switch SW, either the dispatcher selectively closes contact 19 or the engineman reaches out from the cab and grasps circuit controlling device HS, which is located along the track and closes contact 19. This energizes relay RI {which remains ergized because of the closing of its contact 1 in parallel with contact 19. The energizing of relay RI also closes contacts I and 26 and opens back contact 3I.

With contact I5 closed, electromagnetic valve ML is energized causing lock plunger LP to withdraw from control rod 61 and contacts L02, L03 and LC4 to close and contact LCI to open.

The opening of contact LCI opens the circuits of both signals SI and S3. The closing of contacts L02 and 2B in the circuit of magnetic valve MI results in this valve being energized so that switch mechanism SM will function to reverse or openswitch SW. Before switch SW has entirely completed its stroke, circuit controller CI is open but since circuit contact LC4 is closed in parallel with Cl, relay RI continues to remain energized so that the movement of switch SW is completed. As the switch moves from the normal or closed to the reverse or open position, circuit contact C5 opens so that magnetic valve ML becomes de-energized, but look plunger LP cannot enter control rod 61. When the switch SW is fully reversed and because ML is de-energized, the spring 239 (Fig.5) forces lock plunger LP into the recess in control rod 61. With the control rod 61 becoming locked by the plunger LP, circuit controllers LCI, LC2, L03 and LC4 are restored to their normal condition. With the switch in the reverse position and locked, magnetic valve MI and relay Rt become de-energized since contact CI and LC4 for relay RI are open, and contacts LC2 and 26 are open for magnet valve MI.

When the switch reaches the reverse position,

contact C4 is closed, and when the switch is locked contact LCI closes so that signal SI clears for the train II1 to proceed over the switch and enter the passing siding. When the train is in track section F, relay TFxis deenergized, opening contacts 34, 45, 60, H, 23 and 12. ,Contact 45 opens the circuit for signals SI and C3 and place signal SI at stop. Contact 34 is open in the circuit of relay R2. Contact GII is" open in the circuit of signals S2 and S4. Contact i I is open in the circuit of valve magnet ML. Contact 23 is open in the circuit of valve magnets MI and M2.

As the train proceeds the flanges of the wheels contact with bar FLB forcing it forward in the direction of the travel of the train, or position 1) (see Figs. 4 and 5) locking control rod I8I by plunger 65 entering recess of I8! and facing point lock casting I15. As the rear end of the train passes over the switch and the flanges of the wheels leave bar FLB, it returns to its normal condition through the force exerted by springs I19 and I96 withdrawing lock plunger 65 from the facing point lock FPL. During the interval that the train is proceeding over the switch and the bar FLB has been in the position b, circuit controller 58 connected with rod 64 has been open, but as soon as bar FLB returns to its normal position this circuit controller is closed.

As the train proceeds into the siding, relay T6 of track section G is de-energized, opening front contacts 52, H, 13 and 14, and closing back contacts 28, 13 and 14. Contact 52 is open in the circuit of signals S2 and S4. Contact H is open in the circuit of signals SI and S3. Contact 2B is closed in the circuit of relay R2. While TF and TG are tie-energized, signals SI, S2, S3 and S4 must remain at stop.

As the rear of the train leaves section F, relay 'I'F again becomes energized, closing front contact 34 in the circuit of relay R2; front contact 45 in the circuit of signals SI and S3; front contact 60 in the circuit of signals S2 and S4; front contact II in the circuit of valve magnet ML, and front contact 23 in the circuit of valve magnets MI and M2.

Since the rear end of the train is still in section G, relay 'IG is still de-energized with contact 52 open in the circuits of signals S2 and S4, and contact 40 open in the circuits of signals SI and S3. As contact 28 is closed on its back point, relay R2 is now energized by way of back contact 3| closed, front contact 34 closed, and contact C2 closed. With relay R2 energized, front contacts 39 and I9 are closed, and back contact 2 is opened. The closing of front contact l9 energizes the valve magnet ML by way of contact CB closed, while the switch is reversed, and contact I I closed. With valve magnet ML energized, lock plunger LP is withdrawn from control rod 61, closing contacts LC2, L03 and LC4, and opening contact LCI. The closing of contact L02 with front contact 39 closed, energizes valve magnet M2, which causes air to enter chamber 231 of the cylinder of SM, closing the switch SW. As the switch closes, or returns to normal, contacts of circuit controller SCC are made and broken in the following order: C4 and C6 are broken, CI made, C2 broken, C5 and C3 made. When contact C8 is open, magnetic valve ML Is de-energized, but upon the switch again reaching full normal position, lock plunger LP is forced into the recess of control rod 51 by spring This causes contacts LCI, 1C2, LC3 and LC4 to assume their normal position, so that valve magnet M2 is de-energized, and relay R2 is de-energized. With contact LCI closed and contact C3 closed, signal S3 is in a condition to indicate proceed, except for contacts 49 and 4| still being open and the train in the block on the main line between switches SW.

As the rear end of the train leaves track section G relay TG becomes energized, restoring its various contacts to their normal positions.

Cmnmunication between conductor and engmeman and dispatcher as train approaches and enters siding. When the train is in section D, transformer WD is automatically disconnected from the intermediate circuit. While the train is passing through section D, any communication between conductor and engineman or between train and dispatcher, must be carried on through the combined intermediate circuits of sections C and E already described, and transformer WF. As the rear end of the train clears section D, moving in direction DS, the train is wholly within intermediate circuit E, and any communications taking place either between rear end and head end or train and dispatcher will be by way of conductors I01 and I09 and transformer WF.

While the train is in section F transformer coil WF is eliminated from the communication circuit. During this period any communication between conductor and engineman or between train and dispatcher must be through the combined intermediate circuits E and I and a transformer WK (not shown) at the far end (not shown) of intermediate circuit 1.

As the train proceeds into the siding and section G, but also is still in section F, any communication taking place between conductor and engineman or train and conductor, will be by way of the combined intermediate circuits E and H and transformer WF. This same channel for communication exists when the train is in section G, and has cleared section F restoring intermediate circuit I to its normal condition.

When the rear end of the train passes over the switch SW, the conductor will so advise the engineman that the train may be stopped to clear the fouling point with the mainline, providing a stop of the train is necessary.

When the train is wholly within the intermediate circuit H, the conductor will report the presence of the train on the siding to the dispatcher, the channel of communication being by way of transformer WG, which is automatically connected to the dispatcher's line by the train being in the circuit of relay TH. This information from the conductor of the train on the siding will be authority for the dispatcher to operate selector 1'! to close contacts 56 and 49 that signal S2 may clear for the train on the main line to proceed in direction DN, and for signal 53 to clear as soon as the train on the main line has passed by it and out of its block.

Train on main line proceeds.As has heretofore been explained, signals S2 and S4 are controlled by contact 58. Should bar FLB fail to return to its normal position unlocking control rod lBl, signals S2 and S4 would not clear. As the train which has kept the main line between the switches SW proceeds in the direction DN, its flanges and wheels come in contact with bar FLB, forcing it forward in the direction DN of the train, or position a, (Fig. 5), withdrawing the lock plunger 65 further away from control rod l lll. Should the switch SW be in the reverse position, the train on the main line could trail through the points without damage resulting. Further a train on the siding may come out on the main line trailing through the switch, which is in its normal position, without damage resulting.

Communication between conductor and engineman and dispatcher as train approaches and enters siding, Fig. 12.-When the train is in section Fl, the normally separate intermediate circuits El and Hl-Il are transposedly connected together in one combined intermediate circuit or communicating zone. The inductor H5 on the train is located to be in inductive, or communicative relationship with conductors 400, 403, 405 and II" on the track as the train progresses, so that any communicating signals passing between conductor and engineman or either of these and the dispatcher must be by way of these conductors.

While the train is in section Fl transformer WFI is eliminated from the intermediate circuit by reason of back contact II being open. During this time conversation between the train and the dispatcher is by way of transformer WKl and conductors DI and D2.

The method of signaling, transmitting and receiving communications,-as to the equipment on the train and in the dispatchers oflice, is the same as heretofore explained.

Communication between conductor and engineman and dispatcher and between attendants on two trains and/or between the attendants on one or both trains and the dispatcher while in intermediate circuit H1-I1 Fig. 12.While a train is in siding, inductors H5 of the train are in inductive, or communicative relationship with the conductors 403 and 405 of the intermediate circuit Hl-II. The same is true for a train on the main line. The dispatcher is in communicative relationship with intermediate circuit Hl-Il through transformer WKI. Any communication passing between rear end and head end of either train, or between the two trains, or between either or both trains and the dispatcher must be through intermediate circuit Hl-II.

The procedure in signaling, transmitting and receiving communications between the rear end and head end of a train, and between the dispatcher and a train has heretofore been explained. This procedure between two trains is identical with that of carrying on communication between the rear and head ends of a train. It is readily seen how the parties on the two trains and the dispatcher may communicate together. Such a form of communication will often be desirable in a system for operating trains where the dispatcher desires to give instructions to the two trains in regard to their further procedure and both trains are mutually concerned.

A train on the siding proceeding to the main line-As a further detail in the operation of train, assume a train in the siding bound in the direction DN waiting for a train on the main line and that this latter train has just passed through. After the dispatcher instructed the train bound in the direction DN to enter the siding, he operated selector relay 18 to open contact H to place signal S4 at stop as a precaution against the train leaving the siding until proper for it to do so. Now that the main line train has passed, the dis patcher operates selector relay 18 again to close contact II that signal S4 may clear for the train to leave the siding. In case further orders are necessary, the same may be issued to the train on the siding before signal SI clears. The procedure in issuing orders to a train has already been described. As arranged in Fig. 3, the circuit for signal S4 is not dependent upon the position of the switch SW. It is, however, governed by the position of the approach locking means. If the facing point lock FPL is unlocked, contact 58 in the circuit of signal S! is closed and, with its block clear, signal S4 will clear. The switch SW may be set for train movements along the main line, but the train on the siding may proceed trailing through the points of switch SW which is permissible because of the spring and buffer connection SB joining the mechanism SM to the control rod l8l for the switch. As the train proceeds through the switch, the wheels contact with bar F'LB operating same to keep switch points unlocked that the latter will be free to be moved over as the wheel flanges force them over. When the train has cleared the switch, points I and I9! return slowly to their normal position because of the spring and buffer action.

Operation of switch SW by dual switch stand.- In the case of a train desiring to enter the siding and it should be found impossible to operate the switch SW by the power means provided, as illustrated in Fig. 3, an attendant of the train may operate the switch with the dual switch stand. Lever ISO is first thrown over, which operation causes lock plunger LP to be withdrawn from rod 61 and lever Hi to be connected to switch rod "2. Lever ill is next thrown over, which operation reverses switch SW. The withdrawing of plunger LP from rod 61 causes circuit contact L! to open in the circuits of signals SI and 83, holding these signals in the stop position. The train may now proceed into the siding under the usual hand signal of the trainman and the procedure prescribed by the railroads for making train movements against stop signals. As the train proceeds, relay TF is de-energized, facing point lock FPL is operated to lock the switch, relay TG is de-energized and relay TH is de-energized the same as would be the case if the train entered the siding after theswitch had been onerated by the power means provided. Alter the train has entered the siding the attendant oi the train returns the switch SW to its normal position by restoring levers ill and IE0 respectively to their normal positions.

Genera-While my disclosure shows amplification of transmission as well as of reception of communicating signals, I do not wish to be confined strictly to such use, nor to the stages and form of amplification illustrated. For some of the features and under some conditions, amplification of the signals on transmission only is necessary. Under other conditions amplification of the signals when received is suflicient. Generally, amplification of the signals at transmission is desirable in order to put all the power necessary into the intermediate circuit to raise the energy of the communicated signals above the energy of foreign induced currents that cause bothersome noises in the receiver. Amplification or received signals also amplifies the energy oi noise currents which may be in the circuits between the transmitting and receiving points, and not eliminated.

Should the parties concerned in communicating between the two ends of a train or between the train and the wayside station so desire, a code of signals for communication by the signaling means described may be used, instead of always resorting to telephoned communications. particularly true for communicating between conductor and engineman where oftentimes a code of signals for certain brief messages would be less trouble than telephone conversation.

Contact 19 for reversing switch SW may be operated by manual means from the ground or the locomotive or by mechanical means carried on the locomotive; or it may be closed inductively as disclosed in my co-pending application Serial #198,824; or it may be closed by a selector under the control of the dispatcher's selective system. For some railways, this latter method 101' closing contact 19 in the operation of the switch SW is preferable for all switches, or part of the switches, in the stretch where the system de scribed is installed.

Electromagnetic valve ML may be controlled by a contact ll operated by bar 64, closed when bar 64 is in normal position and open otherwise, instead of a contact ll operated by track relay TF. Such an arrangement would also make impossible the operation of power mechanism SL to withdraw lock plunger LP while a train is on the switch SW. Similarly electromagnet valves MI and M2 may be likewise controlled; i. e., instead of contact 23 being controlled by relay TF it may be controlled to be closed when bar 64 is normal but open otherwise. With such an arrangement neither Mi or M! could be operated while a train is on the switch SW. Since valve magnet This is ML is controlled by a contact ll operated by either relay TF or bar 64 and valve magnets MI and M2 are controlled through LC2 by the operation of magnet ML, contact 23 for the controlling oi magnets MI and M2 is but an extra precaution.

Relay R2 may also be operated by a contact 34 controlled from bar 64 instead of from relay TF, such contact 34 being closed with bar 64 in normal position but open otherwise. Such an arrangement would prevent switch SW being operated on the closure of contact 28 to energize relay R2 with a train in contact with bar FLB to lock the switch at F'PL.

In the invention disclosed in this application I have described the use of a conductor located on the track as part of the closed metallic intermediate circuit, for transmitting and receiving communicating signals, particularly as this construction lends itself readily to minimizing and eliminating the effects of any foreign electrical currents which would otherwise cause bothersome noise disturbances.

In my co-pending application, Serial #227,932, I use the track rails as a part of the closed metallic intermediate c rcuit for transmitting and receiving the communicating signals, such an arrangement being desirable particularly from the standpoint of safety, the cost of construction and maintenance, and convenience in the arrangement of means for co-operation between train carried and Wayside devices.

It is now apparent that in applying this systern of communication to some stretches of railroad both types of intermediate circuits may be used; in some territories the track rails and in other territories of the same stretch the conductor located on the track may be the medium for transmitting and receiving the communicating signals passed between the train and the wayside and between the two ends of the trains.

The inductor on the train may be located to co-operate in transmitting and receiv n with either or said types of intermediate circuit.

What I claim as new is:

1. In a system adapted for communicating between the two ends of a railway train and/or between a railway train and a wayside station, in combination, transmitting and receiving means on each end or the train,;transmi ttlng and receiving means in the wayside station, an intermediate circuit composed of transposed conductors connecting together said train end means and means in said circuit adapted to be operated to connect said train end means with said wayside station means, the arrangement being such that the communication characteristics of said intermediate circuit are constant, and means amplifying the communicating signals as transmitted between said train ends and/or between said train ends and said wayside station.

2. In a system for communicating between the two ends of a railway train on a stretch of track and/or between said train and a wayside station, an intermediate circuit associated with the track rails of said stretch, said intermediate circult being comprised of conductors and a transformer in circuit therewith, said conductors being connected in transposed relationship at inwayside station, a series of intermediate circuits, each connecting between said sets as the train moves over the railroad, and means operative to connect adjacent circuits of said series together in transposed relation.

4. In a system for communicating between the two ends of a railway train on a stretch of track and/or between the railway train and a wayside station, an intermediate circuit comprising transposed conductors along said stretch, a transformer in circuit with said conductors, and means at the ends of said stretch connecting the conductors together, said means being adaptable to join said circuit to an adjacent similar intermediate circuit and to eliminate the transformer from said first named circuit while the two intermediate circuits are Joined.

5. In a system for communication between the two ends of a railway train and/or between the railway train and a wayside station, a signalling means on each train end and in the wayside station, said signalling means including a source of energy of a prescribed frequency for said train ends and said station to give a certain signal when transmitted from said train ends and a different signal when transmitted from said station, an intermediate circuit connecting between said train ends and said station in electrical relation with all or said means, and means amplifying the signals transmitted between said train ends and said station.

6. In a system for communicating between the two ends oi a railway train and/or between two railway trains, a stretch of parallel tracks for trains, a transmitting and receiving communicating set on each end of said trains, and an intermediate circuit in inductive relation with said train sets, said intermediate circuit comprising a conductor on the wayside of each of said tracks and circuit controlling means at the ends of said stretch connecting said conductors together.

7. In a system for communication between the two ends of a railway train and/or between the railway train and a wayside station, a signalling means on each train end and in said station comprising, a source of energy oi. a prescribed frequency, a circuit means for transmitting the energy impulses from said source, a condenser for making said circuit resonant or nearly so to said frequency, and an auxiliary circuit connected to said energy source including a device responsive to the i'requencyof said current source operative to indicate when said source is operating in said transmitting circuit.

8. In a system for communicating between the two ends of a railway train and/or between the railway train and a wayside station, a transmitting and receiving set comprising, a normally open transmitting circuit, a normally closed receiving circuit, means in said transmitting circuit for sending out calling signals and voice signals and for amplifying only said transmitted voice signals, means in said receiving circuit for receiving calling signals and voice signals and for amplifying the same, and devices responsive to said received amplified calling signals and voice signals.

9. In a system for communicating between the two ends of a railway train on a stretch of track and/or between the railway train and a wayside station, an intermediate circuit comprising, transposed conductors along said stretch, and means connecting the ends of said conductors together,

said means being adaptable to Join said circuit to another intermediate circuit of said stretch.

10. In a system for communicating between the two ends or a railway train and/or between the railway train and a wayside station, an intermediate circuit in the track wayside system of a stretch 01 parallel tracks for trains, comprising a conductor on the wayside of one of said tracks, a conductor on the wayside oi the other of said tracks, a transformer at one end of said stretch in series with said conductors, and means operative by passing trains connecting said conductors together at each end of said stretch.

11. In a system for communicating between the two ends of a railway train and/or between the railway train and a wayside station, a stretch of parallel tracks for trains, a transmitting and receiving communicating set on each train end and in said .wayside station, and an intermediate circuit in inductive relation with said train sets and adapted to be connected to said wayside railway train and a wayside station, a stretch of track for the train, a telephone line and selective system for said stretch connecting with a transmitting and receiving communicating set in said wayside station, a series of electrically independent intermediate circuits for said stretch each adapted to be selectively connected with said telephone line by said selective system, and a transmitting and receiving communicating set on each train end in electrical relation with said intermediate circuits for normally maintaining communication between said train ends.

13. In a means for communicating between the rear end and head end of a railway train on a stretch of track, a wayside system comprising, a plurality oi conductors generally parallel to said track and connected together at intervals to form a series of intermediate circuits, and means in said circuits controlled by the train transposing said conductors with reference to each other and to the rails in said track.

14. In a means for communicating between the rear end and the head end of a railway train on a stretch of track, a wayside system comprising, a series of pairs of conductors, and operable means associated with said track connecting said pairs at each end to form a series oi electrically separate and independent circuits, said means when operated being adapted to connect together adjacent circuits of said series.

15. In a means for communicating between a railway train on a stretch of track and a wayside station, a wayside system comprising, a wayside communicating circuit connecting to the wayside station, conductors along said stretch transposed at intervals, means operatively associated with said stretch connecting said conductors together to form an intermediate circuit including said transpositions, and means operative from said wayside station adapted to connect the. communicating circuit with said intermediate circuit.

16. In a means for communicating between a railway train on a stretch of track and a wayside station, a wayside system comprising, a wayside communicating circuit connecting to the wayside station, a series of pairs of conductors along said stretch, means associated with said stretch normally connecting said pairs at each end to form a series of electrically independent circuits, and means adapted to connect the communicating circuit with each of said series of independent circuits, some of said means being governed from said wayside station and other of said means being governed from said track.

17. In a system for communicating between a wayside station and a railway train and/or between the two ends of a railway train, in combination, transmitting and receiving means on each end of the train, an inductor and circuit in each of said train means, a closed conductive wayside circuit in a constant inductive relation with said inductors, a wayside transmitting and receiving means, means associated with said wayside circuit and controlled from the wayside station adapted to connect said wayside transmitting and receiving means with said wayside circuit, and means amplifying the communicating signals when transmitted from and received on said train ends.

1'8. In a system for communicating between a vehicle operating in a district and a wayside station, a communication set on the vehicle including a transmitting and receiving means and an amplifier of communication signals, a wayside station communicating set including transmitting and receiving means, a series of separate and independent wayside mediums for carrying communication impulses, each adapted to be in communicative relation with the vehicle communication set, and means controlled from the wayside station adapted to communicatively connect the wayside station communication set with any one or more or said mediums.

19. In a system for communicating between a wayside station and a vehicle in a stretch of track, a wayside system comprising, a series of intermediate circuits for said stretch, each of the series being a circuit separate and distinct from the other circuits of said series and composed of transposed conductors, a wayside communicating circuit connecting to the wayside station, and means adapted to place the wayside communicating circuit in communicative relation with any one or several 01' said intermediate circuits.

20. In a system for communicating between the two ends of a railway train in a stretch of track, a wayside system comprising, a series of intermediate circuits for the stretch, each of the series being a circuit normally separate and distinct from the other circuits or said series, and means operative to transform adjacent circuits of said series into one enlarged intermediate circuit also separate and distinct from the other adjacent circuits of the series.

21. In a system for operating trains over a stretch of trackunder the control of a dispatcher,a passing siding in said stretch, a train on said passing siding bound in a. certain direction, a moving train in said stretch bound toward said passing siding, signals at said passing siding governing train movements over the switches 'of said siding and a circuit for each of said signals, communicating means on said trains and in the dispatchers ofiice, normally electrically isolated intermediate circuits for said stretch, including the passing siding, in communicative relation with said train communicating means and adapted to be placed in communicative relation with the dispatchers communicating means. track circuits controlling both said signal circuits and said intermediate circuits, and selective means operative by the dispatcher tor connecting the dispatchers ofilce communicating means with said intermediate circuits and for controlling the circuits of said signals, the arrangement being such that after the dispatcher has communicated with the trains and given them instructions, he may operate said signals as a check on his instructions to hold the train on the siding and to permit the moving train to proceed without stopping.

22. In a system for operating a train over a stretch of track under the control of a dispatcher,

a main line and a siding in said stretch adapted to be connected together by a switch, signals for governing the train over the switch, means for exchanging communications between the train and the dispatcher, selectively operated means controlled by the dispatcher controlling the indications of said signals and said exchange of communications while the train is approaching said siding, and means controlled by the train controlling said exchange of communications while the train is on said siding.

23. In a system under the supervision of a dispatcher for operating railway trains, a stretch of track for trains including a main line and a siding adapted to be connected together by a switch, a normally clear signal S4 governing trains over the switch from the siding to the main line, a normally clear signal S3 governing trains over the switch along the main line in a direction facing'the switch, a normally clear signal S2 governing trains over the switch along the main line in a direction trailing the switch, a circuit in communicative relation with trains occupying said stretch of track, a dispatchers line, and means selectively controlled by the dispatcher over said line for controlling the indications of said signals and for connecting said circuit to the line.

24. In a system for operating railway trains, a stretch of track for trains, operating under the supervision of a dispatcher, including a main line and a siding adapted to be connected together by a switch, means for exclusive communication between any one of said trains and the dispatcher, said communications being receivable on and transmittable from said train, a power mechanism for operating said switch to open and close the same, means selectively controlled by the dispatcher controlling said communication means. that the dispatcher may instruct said one train to enter the siding, and contolling said power mechanism to open said switch, that the train may enter the siding, and means controlled by said train, efiective after passing over the switch, controlling said power mechanism to close said switch and controlling said communication means that the train may advise the dispatcher of its arrival on said siding.

25. In a. system for communication between a plurality of railway trains in a stretch of track and a wayside station, means on each train for transmitting a signal and receivin a distinctively different signal, means in the wayside sta tion for receiving said signal transmitted from the train and for transmitting said distinctively different signal to the train, and means associated with said station for selectively placing the transmitting and receiving means of said station in operative relationship with the transmitting and receiving means on one or more than one of said trains.

26. In a system for communication between the two ends of a railway train and/or between 

